﻿using System;
class Demo
{
    public static int Main()
    {
        Console.WriteLine("请输出两个数字及运算符");
        int a;
        double b;
        double result = 0;
        char c;
        a = Convert.ToInt32(Console.ReadLine());
        b = Convert.ToDouble(Console.ReadLine());
        c = (char)Console.Read();
        switch (c)
        {
            case '+':
                result = a + b; break;
            case '-':
                result = a - b; break;
            case '*':
                result = a * b; break;
            case '/':
                result = a / b; break;
            default:
                Console.WriteLine("运算符输入错误，请重新输入");
                return 0;
        }
        Console.WriteLine("运算结果是：" + result);
        return 0;
    }
}